Our proposed network brings together 18 investigators from diverse disciplines/research traditions to address key areas of methodological development needed in order to advance studies of oncologist-patient communication concerning treatment decision making, particularly related to clinical trials sponsored by cooperative groups supported by the NIH. Social/behavioral scientists and medical/surgical oncologists will share their expertise (over two years, via teleconferencing, website technology, and two meetings) regarding a) psychophysiological stress responses; b) individual/family influences on patient decision making; c) pattern detection and sequencing of interdependent biobehavioral and interpersonal data; d) the context and content of experimental surgical oncology treatments and problems of accrual to trials. Specific aims: 1) To advance methods and analytical strategies to capture and integrate simultaneous and sequential interdependent biobehavioral and interpersonal factors that facilitate or impede treatment decision making; 2) To seek pilot data to implement and evaluate this newly developed interdisciplinary methodology to address the problem of patient accrual to surgical oncology trials. Interdisciplinary interaction is needed among members of this network to address three methodological needs: the identification of strategies to capture interdependent biopsychosocial data, the capture of real-time self-report data reflecting patient decision-making outside the medical encounter, and the linkage of these multiple levels of data and methods analytically using advanced pattern detection techniques to predict and explain outcomes. Long term goals are to conduct a multi-site ACOSOG cooperative group trial using our methods to test a biopsychosocial intervention designed to reduce perceived risks/costs and benefits of participating in surgical oncology trials and to broadly disseminate this methodology to inform many other relevant areas of medical and health research involving interpersonal interaction and mutual influence under stressful conditions.